The Sony FE 50mm f/1.8 is a budget full-frame 50mm lens for the Alpha mirrorless system. Optics are sound, but its autofocus motor is sluggish.

The FE 50mm F1.8 ($249.99) is Sony's take on a low-cost prime lens for its full-frame mirrorless camera system. It captures a standard-angle field of view and offers a wide f/1.8 maximum aperture so you can blur backgrounds behind your subject and capture photos in subpar light. But it's on the pricey side for what it is, and is held back by some optical shortcomings when shot wide open. More annoyingly, its autofocus motor takes a long time to lock onto a target. There aren't a lot of alternatives available at this price point, however, so photographers on a tight budget may still find it to be a good choice. But our recommendation is to save your pennies and get the Zeiss Sonnar T* FE 55mm F1.8 ZA instead.

Design

The FE 50mm is small and light. It measures 2.3 by 2.7 inches (HD) and weighs just 6.6 ounces. The front element supports 49mm filters. Its barrel is sturdy polycarbonate and its lens mount is metal—it doesn't feel like a cheap lens. But neither does the very similar Canon EF 50mm f/1.8 STM, which sells for about half the cost. Sony includes a lens hood with the FE 50mm; you have to buy one separately with Canon's nifty-fifty, a nickname first applied to EF 50mm, but which has spread to other inexpensive 50mm optics.

The lens covers a full-frame image circle, and is likely going to be on the radar of Alpha 7 II owners in want of a prime that gathers a lot of light and won't break the bank. It's not optically stabilized, but the Alpha 7 II offers in-body stabilization. If you shoot with an APS-C E-mount camera, like the Alpha 6000, the E 35mm F1.8 or E 50mm F1.8 are better fits.

The FE 50mm doesn't sport any toggle switches. It has a rubberized manual focus ring. Manual focus is an electronic affair—turning the ring activates the motor, which moves the lens elements. That's typical for a Sony mirrorless lens. If you love the feel of manual focus, you can stick within a budget and use an old SLR lens via an adapter, or opt for the pricey Zeiss Loxia 2/50.

Autofocus isn't speedy. Focus speed isn't something we typically hit on in lens reviews, because it's usually really quick. But the FE 50mm requires a full 0.4-second to lock focus and fire a shot when paired with the Alpha 7R II. When paired with the Sonnar T* FE 55mm F1.8 ZA, the A7R II focuses and fires in half the time, 0.2-second. That itself is on the slow side; 0.4-second can seem like an eternity when you're trying to capture a candid moment.

Focus is possible to 1.48 feet (0.45-meter), which delivers a modest 1:6.7 life-size magnification ratio. If you want to work closer, consider a macro lens instead. Sony sells the FE 50mm F2.8 Macro for about $500; we haven't yet tested it, but it may prove to be a solid option for photographers in want of a more versatile 50mm.

Image Quality

I tested the FE 50mm F1.8 with the 42MP Alpha 7R II. Owners of a high-end body might not reach for this lens when there are more premium options like the FE 55mm F1.8 and the Planar T* FE 50mm F1.4 ZA ($1,499.99) available, but we try to streamline lens testing on a single body for better cross-comparison of optics within a system.

At f/1.8 the 50mm scores 2,666 lines per picture height on Imatest's standard center-weighted sharpness test. That's better than the 2,200 lines we look for from a lens paired with a high-resolution camera, but image quality is not even from edge to edge. The center third of the frame is razor sharp (3,198 lines), but it quickly gives way to softness as you move away, with the middle third showing just 1,902 lines. That's not a terrible result, and if you center your subjects when shooting at a wide setting, any weakness will be hidden by the shallow depth of field.

The lens performs slightly better at f/2 (2,741 lines). At f/2.8 it gets a lot sharper, scoring 3,212 lines on average with superb performance at the center (4,113 lines), matched with lesser, but strong quality in the middle third (2,673 lines) and edges (2,218 lines).

The trend continues at f/4, with the average score improving to 3,306 lines, with modest improvements across the frame. At f/5.6 the lens is near its crispest (4,202 lines), with very even performance across—the edges are just shy of 4,000 lines. Absolute best performance is at f/8 (4,294 lines), with scores starting to drop at f/11 (4,005 lines) and f/16 (3,673), but it's not until f/22 (2,381) that there's a detrimental loss in image fidelity.

I noticed very heavy purple color fringing (chromatic aberration) in test shots at f/1.8 and f/2. It's lessened at narrower apertures. It's particularly noticeable toward the edges of the frame, as well in areas with high contrast between light and dark subjects. You can remove it with some work in Lightroom, but be aware you'll be using the Defringe tool and Remove Chromatic Aberration checkbox often with this lens.

Distortion isn't an issue in field conditions; the FE 50mm isn't free of it, but it's modest enough to be negligible. Corner illumination is a minor issue at wide apertures. I used an ExpoDisc to shoot a flat gray image at each f-stop and analyzed the photos using Imatest's Uniformity tool. At f/1.8 there is a 1.8-stop (-1.8EV) drop in illumination at the corners of the frame when compared with the center. The deficit is -1.4EV at f/2, but is less than a stop (-0.8EV) at f/2.8. You may want to brighten the edges of shots at f/1.8 and f/2, but the vignette effect is barely noticeable beyond that.

Conclusions

The Sony FE 50mm F1.8 comes in at a low price compared with other lenses in the Sony mirrorless system, which trends to the expensive side as it is. It delivers excellent center sharpness when shot wide open, and is crisp from edge to edge when shot at narrower apertures. But it's not without issues, including excessive color fringing when shot with the iris open, which is visible when images are enlarged. The real stickler is the focus speed—it's just too slow for a modern lens, even one marketed as a budget option. We haven't tested the $500 FE 50mm 2.8 Macro yet, but at $500 it's certainly an option for Sony mirrorless shooters who want a 50mm that doesn't break the bank, but also doesn't skimp on performance. If you want a wider aperture, however, our Editors' Choice remains the pricey, but excellent, Zeiss Sonnar T* FE 55mm F1.8 ZA.

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About the Author

Senior digital camera analyst for the PCMag consumer electronics reviews team, Jim Fisher is a graduate of the Rensselaer Polytechnic Institute, where he concentrated on documentary video production. Jim's interest in photography really took off when he borrowed his father's Hasselblad 500C and light meter in 2007. He honed his writing skills at re... See Full Bio

Sony FE 50mm F1.8

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